Preface: This article covers the steps to check the basic functions of the Z Axis endstops on a Thunder Laser Nova Series machine
The Z axis is the only axis to use two endstops on your thunder laser. The Z axis uses the Auto Focus eyes as the upper endstop, which is Zlimit- in the controller. The Zlimit+ is the lower endstop towards the bottom of the machine. The naming convention may seem odd, Zlimit- is higher than Zlimit+ but it makes more sense when you think about how the Z=0 is the upper position and the value of the Z position increases as you lower the bed further away from the Laser Head.
Since the Z axis is not homed during startup (prevents crashes) it is given an arbitrary value (3000mm) at startup, but once you do and Auto Focus or manually reset the Z Axis from the Ruida DSP on the machine, the Z axis will be assigned a new value. For Nova series machines that do not use a home offset, the new value is 0. The machine will not let the Z axis travel into the negative space, so you may have to re-home if you remove materais\the honeycomb out and want to establish a higher Z=0 reference point.
The lower Z Axis limit switch prevents the honeycomb crashing down into the crumbtray, belts, or bottom of the machine. Since the machine can operate with an obscure value (Z=3000mm + travel distance if not homed\autofocused) then the soft limits(machine software setting) cannot prevent a crash so the hard limit (endstop) to prevent the crash.
From the controller home page, press the MENU button then scroll down to Diagnoses+ (right side middle of options) and press Enter.
LED OFF (Not Blocked) | LED ON (Blocked or not seeing left side) |
Older Style | Older Style |
Newer Style | Newer Style |
LED OFF (Not Blocked) | LED ON (Blocked or not seeing left side) |
Zlimit- Triggered on Diagnostic Screen (Blocked or not seeing left side sensor) | ZLimit- LED5 Illuminated on Ruida Controller (Blocked or not seeing left side sensor) |
Since the lower endstop is a mechanical switch and there is only one of them and it does not have LED lights, it will be easier to check since the signal can only be checked Visually for damage and then at the Diagnostic Screen or from the LED lights on the Ruida Controller.
Visually inspect for damage to the arm. Make sure the arm is not bent out of shape and that the "Clicking" function still works. A gentle press of the arm is all you need to make it click.
Verify the signal is making it to the controller. You can use the diagnostic screen on the controller or the Red LEDs on the physical controller. The LED will light up when the sensor is blocked. If the LED on the Auto Focus sensor comes on but LED5 for Zlimit- does not light up, then there is a wiring or output issue from the Auto Focus Sensor (endstop) to the controller.
Zlimit+ Triggered, arm is depressed on Diagnostic Screen | Zlimit+ is triggered - LED6 Illuminated on Ruida Contrlller |